Image Item No. Description By  4185  Technic Wedge Belt Wheel (Pulley) Catalog: Parts: Wheel 14  30027a  Wheel 8mm D. x 9mm for Slicks, Hole Round for Wheels Holder Pin Catalog: Parts: Wheel 1  13971  Wheel 18mm D. x 8mm with Fake Bolts and Deep Spokes with Inner Ring Catalog: Parts: Wheel 14